Coater/developer, method of coating and developing resist film, and computer readable storing medium

ABSTRACT

A transfer flow is produced in accordance with a process recipe of a process to be carried out. In the transfer flow, a type of modules listed in accordance with a substrate transfer order is associated with a necessary staying time from when the substrate is transferred into a module by a substrate transfer unit to when the substrate is ready to be transferred back to the substrate transfer unit after the corresponding process is finished. A cycle limiting time is determined to be the longest necessary transfer cycle time among those obtained by dividing the necessary staying time by the number of the modules mounted in the coater/developer. The number of the modules to be used is determined to be a value obtained by dividing the necessary staying time by the cycle limiting time or a nearest integer to which the value is raised.

This application is based on Japanese Patent Application No.2007-266498, filed on Oct. 12, 2007 with the Japanese Patent Office, theentire content of which is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a coater/developer that coats a resistfilm on a substrate such as a semiconductor wafer, an LCD wafer (glasswafer for an Liquid Crystal Display) and develops the exposed resistfilm, a method of coating and developing the resist film, and a computerreadable storing medium that stores a program for allowing thecoater/developer to carry out the method of coating and developing theresist film.

2. Description of the Related Art

In a fabrication process of a semiconductor device or a flat paneldisplay (FPD), photolithography is indispensable in order to form apredetermined resist pattern on a substrate. The photolithographyincludes a series of processes of coating resist solution in order toform a resist film on the substrate such as a semiconductor wafer(referred to as a wafer below), exposing the resist film with exposurelight through a photomask, and developing the resist film. Suchprocesses are generally carried out in a resist pattern formingapparatus having a coater/developer for forming the resist film anddeveloping the resist film after the exposure and an exposure apparatusconnected to the coater/developer.

An example of the resist pattern forming apparatus has been proposed in,for example, Patent-related Document 1. In this apparatus, wafercarriers 10 containing plural wafers W are placed on a carrier stage 11of a carrier block 1A as shown in FIG. 1 and the wafer W in the wafercarriers 10 is delivered to a process block 1B by a transfer arm 12.After a resist solution is coated on the wafer W in order to form theresist film at a coating module 13A in the process block 1B, the wafer Wwith the resist film formed on the upper surface is transferred to anexposure apparatus 1D via an interface block 1C, and the wafer Wundergoes an exposure process. Then, the wafer W is returned to theprocess block 1B and undergoes a developing process in a developingmodule 13B. Finally, the wafer W returns to the original wafer carrier10.

Before and after the resist solution coating process and the developingprocess, wafer temperature control in a temperature control module, awafer heating process in a heating module, and a wafer cooling processin a cooling module are carried out. The temperature control module, theheating module, and the cooling module are arranged one above another inshelf modules 14 (14 a through 14 c). The wafer W is transferred betweenplaces where the wafer W can be placed in the process block 1B such asthe coating module 13A, the developing module 13B and the shelf modules14A through 14C by two transfer units 15A, 15B provided in the processblock 1B.

When the resist film is formed on the wafers W by various processesmentioned above, each of the wafers W to be processed is transferred bythe transfer units 15A and 15B in accordance with a transfer schedulethat determines the wafer W is to be transferred to a predeterminedmodule at a predetermined timing as described in Patent-relatedDocument 1. The transfer units 15A, 15B include two or more arms inorder to hold the wafer W. The way that the wafer W is transferred bythe transfer units 15A, 15B is explained as follows. The transfer unit15A (15B) receives with an arm A1 a wafer W1, which is processed in onemodule M1, from the module M1, and delivers with an arm A2 a wafer W2,which is to be processed after the wafer W1, to the module M1. Then, thetransfer unit 15A receives with the arm A2 a wafer W0, which isprocessed before the wafer W1, from a module M0, which is locateddownstream of the series of the process modules, and delivers with thearm A1 the wafer W1 to the module M0.

While various modules such as the coating module, the developing moduleand the like are mounted in the coater/developer, the number of theincorporated modules is different depending on a type of the modules.For example, the coater/developer may have three of the coating modules,three of the developing modules, and nine of the heating modules for usein heating the wafer W having the resist solution coated. In addition,the coater/developer may have three anti-reflection film formingmodules. However, all the modules mounted in the coater/developer arenot used in every process. Namely, the modules to be used in aparticular process and the number of the modules are specified by anoperator of the coater/developer when the process is carried out.

Specifically, serial numbers are given to all the modules mounted in therelated art coater/developer, and the operator produces a transfer flowthat determines a transfer route of the wafer W by specifying therespective serial numbers given to the corresponding modules inaccordance with the order of the modules to be used. In addition, theoperator selects a process recipe in each of the modules. As a result,the transfer schedule is produced. In this case, the number of themodules of the same type to be used is determined based on his or herexperience.

When the wafer W is transferred in accordance with the transferschedule, a cycle time required to carry out one cycle of the transferschedule is determined. The cycle time is generally determined as alimiting time to be the longest one of necessary transfer cycle times.The necessary transfer cycle time is obtained for each type of modulefor carrying out a same process by dividing a necessary staying timefrom when the wafer W is transferred to a module by the transfer unit15A (15B) until when the wafer W is ready to be transferred from themodule by the transfer unit 15A (15B) after the process is finished inthe module by the number of the modules for the same process. Becausethe necessary transfer cycle time is usually longer than a time periodrequired for the transfer unit 15A (15B) to successively deliver thewafer W to all the accessible modules in the process block 1B, thelimiting time is determined to be the longest necessary transfer cycletime among others, as stated above.

For example, when it is assumed that the coater/developer has threecoating modules whose necessary staying time is 60 seconds and nineheating modules to be used for pre-baking whose necessary staying timeis 90 seconds, the necessary transfer cycle times for the coating andfor the pre-baking processes are 20 seconds (=60/3) and 10 seconds(=90/9), respectively. In this case, a cycle limiting time is thenecessary transfer cycle time for the coating process, which is longerthan the necessary transfer cycle time for the pre-baking process.

On the other hand, only six of the nine heating modules (LHP) arenecessary for the following reasons. When a first wafer W1 is deliveredto a first heating module LHP1 and then a second wafer W2 is deliveredto a second heating module LHP2, the remaining time for the first waferW1 to be heated in the first heating module LHP1 is 70 seconds. When athird wafer W3 is delivered to a third heating module LHP3, theremaining time for the first wafer W1 is 50 seconds. When a fourth waferW4 is delivered to a fourth heating module LHP4, the remaining time forthe first wafer W1 is 30 seconds. When a fifth wafer W5 is delivered toa fifth heating module LHP5, the remaining time for the first wafer W1is 10 seconds. Then, a sixth wafer W6 is delivered to the first heatingmodule LHP1 rather than a sixth heating module LHP6. This is because theheating process for the first wafer W1 is finished by then and the waferW1 is transferred out from the first heating module LHP1, leaving thefirst heating module LHP1 ready for the sixth wafer W6.

Therefore, even when the operator selects nine heating modules, only sixheating modules are used and the remaining three heating modulescontinue to be in an idle state. This situation takes place quite oftenbecause the number of modules to be used is determined in accordancewith the operator's experience, as stated above.

What is worse in this situation is that all the nine heating modulesstart to be heated to 90° C. through 130° C. when selected by theoperator, which leads to a waste of electricity, an increased runningcost and thus an increased fabrication cost.

The inventors of the present invention are trying to reduce the waste ofelectricity and the running cost, which may be caused from the fact thattemperature control is carried out in, for example, the heating modulesthat are not planned to be used. Patent-related Document 1 fails todisclose or suggest a way of reducing the waste of electricity and therunning cost.

Patent-related Document 1: Japanese Patent Application Laid-OpenPublication No. 2004-193597.

SUMMARY OF THE INVENTION

The present invention has been made in view of above, and is directed toa technology that is capable of reducing the waste of electricity andthe running cost in a coater/developer.

A first aspect of the present invention provides a coater/developerapparatus having a carrier block where a carrier housing pluralsubstrates is placed and that has a transfer unit for transferring asubstrate into and out from the carrier, and a process block where acoating film is formed on the substrate transferred from the carrier bythe transfer unit and a developing process is carried out with respectto the substrate after an exposure process, wherein the process blockincludes plural liquid process modules where a coating solution iscoated on the substrate, plural heating modules where the substrate isheated, plural temperature control modules where a temperature of thesubstrate is controlled, and a substrate transferring unit configured totransfer a first substrate out from a first module of the plural liquidprocess modules, the plural heating modules, and the plural temperaturecontrol modules, the first substrate having been processed in the firstmodule, and transfer a second substrate into the first module, thesecond substrate having been processed in a second module locatedupstream from the first module by one process step in a wafer transferroute. The coater/developer apparatus includes a transfer flow producingportion that produces, in accordance with a process recipe concerningthe carrier in the carrier block, a transfer flow where a type of themodules listed in accordance with a substrate transfer order in thetransfer flow is associated with a necessary staying time from when thesubstrate is transferred into any one of the modules by the substratetransfer unit to when the substrate undergoes a corresponding process inthe module and is ready to be transferred back to the substrate transferunit, the necessary staying time being determined corresponding to thetype of the modules; a cycle limiting time determining portion thatcalculates a necessary transfer cycle time by dividing the necessarystaying time by the number of the corresponding modules mounted in thecoater/developer apparatus, the necessary transfer cycle time beingobtained with respect to the modules listed in the transfer flow, anddetermines the longest necessary transfer cycle time to be a cyclelimiting time; and a determining portion that calculates a value bydividing the necessary staying time by the cycle limiting time anddetermines the number of the modules to be used to be one of the valueand a nearest integer to which the value is raised, the number of themodules to be used being determined with respect to the modules listedin the transfer flow.

A second aspect of the present invention provides a coater/developerapparatus having a carrier block where a carrier housing pluralsubstrates is placed and that has a transfer unit for transferring asubstrate into and out from the carrier, and a process block where acoating film is formed on the substrate transferred from the carrier bythe transfer unit and a developing process is carried out with respectto the substrate after an exposure process, wherein the process blockincludes plural liquid process modules where a coating solution iscoated on the substrate, plural heating modules where the substrate isheated, plural temperature control modules where a temperature of thesubstrate is controlled, and a substrate transferring unit configured totransfer a first substrate out from a first module of the plural liquidprocess modules, the plural heating modules, and the plural temperaturecontrol modules, the first substrate having been processed in the firstmodule, and transfer a second substrate into the first module, thesecond substrate having been processed in a second module locatedupstream from the first module by one process step in a wafer transferroute. The coater/developer apparatus includes a transfer flow producingportion that produces, in accordance with a process recipe concerningthe carrier in the carrier block, a transfer flow where a type of themodules listed in accordance with a substrate transfer order in thetransfer flow is associated with a necessary staying time from when thesubstrate is transferred into any one of the modules by the substratetransfer unit to when the substrate undergoes a corresponding process inthe module and is ready to be transferred back to the substrate transferunit, the necessary staying time being determined corresponding to thetype of the modules; a cycle limiting time determining portion thatdetermines the cycle limiting time to be a necessary transfer cycle timeobtained by dividing the necessary staying time in a coating module thatcoats a resist solution on the substrate and is included in the pluralliquid process modules by the number of the coating modules mounted inthe coater/developer apparatus; and a determining portion thatcalculates the necessary transfer cycle time with respect to the moduleslisted in the transfer flow in accordance with the listing order,determines the number of the modules to be used to be one of a valueobtained by dividing the necessary staying time by the cycle limitingtime and a nearest integer to which the value is raised when thenecessary transfer cycle time is less than or equal to the cyclelimiting time, and determines the necessary transfer cycle time to be anew cycle limiting time when the necessary transfer cycle time isgreater than the cycle limiting time and then determines the number ofthe modules to be used to be one of a value obtained by dividing thenecessary staying time by the new cycle limiting time and a nearestinteger to which the value is raised.

A third aspect of the present invention provides a coater/developerapparatus according to the second aspect, wherein the determiningportion recalculates the number of the modules to be used with respectto the modules listed in the transfer flow in the listing order afterthe determining portion calculates the number of the modules to be usedwith respect to the modules listed in the transfer flow in the listingorder.

A fourth aspect of the present invention provides a coating/developingmethod carried out in a coater/developer apparatus having a carrierblock where a carrier housing plural substrates is placed and that has atransfer unit for transferring a substrate in and out from the carrier,and a process block where a coating film is formed on the substratetransferred from the carrier by the transfer unit and a developingprocess is carried out with respect to the substrate after an exposureprocess, wherein the process block includes plural liquid processmodules where a coating solution is coated on the substrate, pluralheating modules where the substrate is heated, plural temperaturecontrol modules where a temperature of the substrate is controlled, anda substrate transferring unit configured to transfer a first substrateout from a first module of the plural liquid process modules, the pluralheating modules, and the plural temperature control modules, the firstsubstrate having been processed in the first module, and transfer asecond substrate in the first module, the second substrate having beenprocessed in a second module located upstream from the first module byone process step in a wafer transfer route. The coating/developingmethod includes steps of producing, in accordance with a process recipeconcerning the carrier in the carrier block, a transfer flow where atype of the modules listed in accordance with a substrate transfer orderin the transfer flow is associated with a necessary staying time fromwhen the substrate is transferred into any one of the modules by thesubstrate transfer unit to when the substrate undergoes a correspondingprocess in the module and is ready to be transferred back to thesubstrate transfer unit, the necessary staying time being determinedcorresponding to the type of the modules; calculating a necessarytransfer cycle time by dividing the necessary staying time by the numberof the corresponding modules mounted in the coater/developer apparatus,the necessary transfer cycle time being obtained with respect to themodules listed in the transfer flow, thereby determining the longestnecessary transfer cycle time to be a cycle limiting time; andcalculating a value by dividing the necessary staying time by the cyclelimiting time, thereby determining the number of the modules to be usedto be one of the value and a nearest integer to which the value israised, the number of the modules to be used being determined withrespect to the heating modules listed in the transfer flow.

A fifth aspect of the present invention provides a coating/developingmethod carried out in a coater/developer apparatus having a carrierblock where a carrier housing plural substrates is placed and that has atransfer unit for transferring a substrate in and out from the carrier,and a process block where a coating film is formed on the substratetransferred from the carrier by the transfer unit and a developingprocess is carried out with respect to the substrate after an exposureprocess, wherein the process block includes plural liquid processmodules where a coating solution is coated on the substrate, pluralheating modules where the substrate is heated, plural temperaturecontrol modules where a temperature of the substrate is controlled, anda substrate transferring unit configured to transfer a first substrateout from a first module of the plural liquid process modules, the pluralheating modules, and the plural temperature control modules, the firstsubstrate having been processed in the first module, and transfer asecond substrate into the first module, the second substrate having beenprocessed in a second module located upstream from the first module byone process step in a wafer transfer route. The coating/developingmethod includes steps of producing, in accordance with a process recipeconcerning the carrier in the carrier block, a transfer flow where atype of the modules listed in accordance with a substrate transfer orderin the transfer flow is associated with a necessary staying time fromwhen the substrate is transferred into any one of the modules by thesubstrate transfer unit to when the substrate undergoes a correspondingprocess in the module and is ready to be transferred back to thesubstrate transfer unit, the necessary staying time being determinedcorresponding to the type of the modules; determining the cycle limitingtime to be a necessary transfer cycle time obtained by dividing thenecessary staying time in a coating module that coats a resist solutionon the substrate and is included in the plural liquid process modules bythe number of the coating modules mounted in the coater/developerapparatus; and calculating the necessary transfer cycle time withrespect to the modules listed in the transfer flow in accordance withthe listing order, determining the number of the heating modules to beused to be one of a value obtained by dividing the necessary stayingtime in the heating modules by the cycle limiting time and a nearestinteger to which the value is raised when the necessary transfer cycletime is less than or equal to the cycle limiting time, and determiningthe necessary transfer cycle time to be a new cycle limiting time whenthe necessary transfer cycle time is greater than the cycle limitingtime and then determining the number of the heating modules to be usedto be one of a value obtained by dividing the necessary staying time inthe heating modules by the new cycle limiting time and a nearest integerto which the value is raised.

A sixth aspect of the present invention provides a coating/developingmethod according to the fifth aspect, further comprising a step ofrecalculating the number of the modules to be used with respect to themodules listed in the transfer flow in the listing order after the stepof calculating the number of the modules to be used with respect to themodules listed in the transfer flow in the listing order.

A seventh aspect of the present invention provides a computer readablestoring medium storing a computer program for use in a coater/developerapparatus wherein a coating film is formed on a substrate transferredfrom a carrier that houses plural substrates and is placed in a carrierblock and a developing process is carried out with respect to thesubstrate in a process block after an exposure process, the computerprogram comprising a group of steps so that the coating/developingmethod according to any one of the fourth through the sixth aspects iscarried out.

According to an embodiment of the present invention waste of electricityand running cost can be reduced because the number of modules to be usedcan be automatically determined in a coater/developer.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, features, and advantages of the presentinvention will become more apparent from the following detaileddescription of preferred embodiments given with reference to theaccompanying drawings.

FIG. 1 is a plan view of a related art coater/developer;

FIG. 2 is a plan view of a coater/developer according to an embodimentof the present invention;

FIG. 3 is a perspective view of the coater/developer according to theembodiment of the present invention;

FIG. 4 is a cross-sectional view of the coater/developer according tothe embodiment of the present invention;

FIG. 5 is a perspective view of a unit block (DEV layer) in thecoater/developer according to the embodiment of the present invention;

FIG. 6 is a schematic cross-sectional view for showing an example of awafer transfer route in the coater/developer according to the embodimentof the present invention;

FIG. 7 is a function block diagram of a control portion of thecoater/developer according to the embodiment of the present invention;

FIG. 8 is a flowchart for explaining a way of calculating the number ofmodules to be used in the coater/developer according to the embodimentof the present invention;

FIG. 9 is an example of a transfer flow in the coater/developeraccording to the embodiment of the present invention;

FIG. 10 is a flowchart for explaining an effect of the coater/developeraccording to the embodiment of the present invention;

FIG. 11 is a flowchart for explaining an effect of the coater/developeraccording to the embodiment of the present invention;

FIG. 12 is an example of a transfer flow in the coater/developeraccording to the embodiment of the present invention;

FIG. 13 is a flowchart for explaining a way of determining the number ofmodules to be used in the coater/developer according to the embodimentof the present invention; and

FIG. 14 is a flowchart for explaining another way of calculating thenumber of modules to be used in the coater/developer according to theembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Non-limiting, exemplary embodiments of the present invention will now bedescribed with reference to the accompanying drawings. In the drawings,the same or corresponding reference marks are given to the same orcorresponding members or components and hence repetitive explanationsare omitted. It is to be noted that the drawings are illustrative of theinvention, and there is no intention to indicate scale or relativeproportions among the members or components. Therefore, the specificsize should be determined by a person having ordinary skill in the artin view of the following non-limiting embodiments.

Referring to the accompanying drawings, a resist pattern formingapparatus including a coater/developer according to an embodiment of thepresent invention is described. FIG. 2 is a plan view of the resistpattern forming apparatus. FIG. 3 is a perspective view of the resistpattern forming apparatus of FIG. 2. FIG. 4 is a side view of the resistpattern forming apparatus of FIG. 2. The resist pattern formingapparatus includes a carrier block S1 where a carrier 20 housing pluralwafers (e.g., 13 wafers) W in an airtight manner are placed, a processblock S2 having plural unit blocks (e.g., 3 unit blocks) B1 through B3arranged in a row, an interface block S3, and an exposure apparatus S4.

The carrier block S1 includes a carrier stage 21 on which the pluralcarriers 20 are placed, an opening/closing portion 22 located on a frontwall that can be seen from the carrier stage 21, and a transfer arm Cserving as a wafer transfer unit for transferring the wafer W into andout from the carrier 20 through the opening/closing portion 22. Thetransfer arm C is movable forward/backward and upward/downward,pivotable around a vertical axis, and shiftable along a direction inwhich the carriers 20 are arranged, so that the wafer W can betransferred into and out from the unit blocks B1 and B2.

The carrier block S1 is connected at a back wall to the process block S2surrounded by a chassis 24. As shown in FIG. 3, the process block S2 issectioned into a first unit block (developer (DEV) layer) B1 where adeveloping process is carried out, a second unit block (bottom coating(BCT) layer) B2 where a bottom anti-reflection film is coated, and athird unit block (coating (COT) layer) B3 where a resist film is coatedon the bottom anti-reflection film, in this order from below in theillustrated example.

Referring to FIG. 4, these unit blocks B1 through B3 have substantiallythe same configuration. Namely, the unit blocks B1 through B3 haveliquid process modules for coating a coating solution on the wafer W, ashelf unit U1 where various modules such as heating modules to be usedfor carrying out a pre-treatment and a post-treatment for the wafer Ware stacked one above another, and a corresponding one of main arms A1through A3 serving as a wafer transfer unit that transfers the wafer Wbetween the liquid process modules and the shelf unit U1.

In an area of the unit blocks B1 through B3 adjacent to the carrierblock S1, a shelf unit U2 is provided so that the transfer arm C in thecarrier block S1 and the main arms A1 through A3 in the process block S2can access the shelf unit U2, as shown in FIGS. 2 and 4. The shelf unitU2 has first passage portions through which the wafer W can betransferred between the unit blocks B1 through B3. In addition, atransfer arm D is provided next to the shelf unit U2. The transfer arm Dis movable forward/backward and upward/downward so that the wafer W istransferred between the passage portions of the shelf unit U2 by thetransfer arm D. Moreover, in an area of the unit block (DEV layer) B1adjacent to the interface block S3, a shelf unit U3 is provided so thatthe main arm A1 of the DEV layer B1 can access the shelf unit U3, asshown in FIGS. 2 and 4. The shelf unit U3 has second passage portionsthrough which the wafer W can be transferred between the process blockS2 and the interface block S3.

Behind the process block S2, an exposure apparatus S4 is connected tothe process block S2 via the interface block S3. In the interface blockS3, an interface arm F is provided so that the wafer W is transferredbetween the second passage portions of the shelf unit U3 of the DEVlayer B1 and the exposure apparatus S4 by the interface arm F. Theinterface arm F is movable forward/backward and upward/downward andpivotable around a vertical axis.

Next, the DEV layer B1 is explained in detail, referring to FIGS. 2through 5. In the center portion of the DEV layer B1, there is atransfer area R1 provided along a longitudinal direction of the DEVlayer B1 (Y direction in FIG. 2). Along the transfer area R1 on theright hand side when viewed from the carrier block S1, developingmodules DEV1 through DEV3 are arranged as the liquid process moduleswhere a developing process is carried out. In addition, developingmodules DEV4 through DEV6 are arranged above the developing modules DEV1through DEV 3, respectively, as shown in FIG. 4.

On the other side of these developing modules DEV, the shelf unit U1having plural process modules in a 3×4 arrangement is located. The shelfunit U1 includes, for example, six heating modules PHP1 through PHP6,which may be called “post-exposure baking modules” where the wafer W isheated after the exposure, and, for example, six heating modules LHA1through LHA6, which may be called “post-baking module” where the wafer Wis heated in order to expel moisture from the developed resist film.

As shown in FIG. 4, in an area of the shelf unit U2 corresponding to theDEV layer B1, temperature control modules CPL11 and CPL12 forcontrolling the wafer temperature are provided that serve as the firstpassage portions. The transfer arm C, the main arm A1, and the transferarm D can access the temperature control module CPL11. The transfer armD and a shuttle arm E (described below) can access the temperaturecontrol module CPL12.

In the shelf unit U3, temperature control modules CPL41, CPL42 andtransfer modules TRS41, TRS42 are provided in this order from below thatserve as the second passage portions. The main arm A1 and the interfacearm F can access these modules CPL41, CPL42, TRS41, and TRS42.

Next, the main arm A1 provided in the transfer area R1 is described. Themain arm A1 transfers the wafer between all the modules in the DEV layerB1, or all the places where the wafer W is supposed to be placed. Themain arm A1 is movable forward/backward and upward/downward, pivotablearound a vertical axis, and shiftable along the Y direction.

The main arm A1 includes two support arms 31, 32 that support a backside circumferential area of the wafer W as shown in FIG. 5. The supportarms 31, 32 are located above a base 33 and independently movable inrelation to each other. The base 33 is located above a transfer basebody 35 and rotatable around a vertical axis by a rotation mechanism. InFIG. 5, “36” denotes a guide rail extending along a longitudinaldirection of the transfer area R1, which corresponds to the Y directionin FIG. 2, and “37” denotes an elevation guide rail. The transfer basebody 35 is movable upward/downward along the elevation guide rail 37.The elevation guide rail 37 is bent at a lower portion into an L-shapeand the bent portion of the elevation guide rail 37 is inserted belowthe guide rail 36 so that the elevation guide rail 37 stands upright.The elevation guide rail 37 is movable along the guide rail 36 so thatthe transfer base body 35 is movable in the longitudinal direction ofthe transfer area R1. When the wafer W is transferred to each processmodule of the shelf unit U1, the elevation guide rail 37 is located at aposition where the elevation guide rail 37 does not block the supportarms 31, 32 from accessing the process module. In FIG. 5, “41” denoteshousing chambers, each of which houses the three developing modules,“42” denotes housing chambers for the process modules, and “43” denotestransfer openings of the housing chambers 42. The wafer W is transferredinto and out from each of the housing chambers 42 through thecorresponding transfer opening of the chamber 42.

The shuttle arm E is a transfer unit arranged in an upper space of theDEV layer B1 and transfers the wafer W exclusively between the shelfunit U2 and the shelf unit U3. As shown in FIG. 5, the shuttle arm Eincludes a support arm 51 that supports the back side circumferentialarea of the wafer W and moves the wafer W along a base 52. The base 52is located above a transfer base body 54 and rotatable around a verticalaxis by a rotation mechanism. The transfer base body 54 is movablyattached on a guide rail 55 provided on a side face of a support member56 arranged at an upper portion of the shelf unit U1, the side facefacing the transfer area R1, so that the transfer base body 54 can movealong the longitudinal direction of the transfer area R1. With such aconfiguration, the shuttle arm E can access the temperature controlmodule CPL12 of the shelf unit U2 and deliver the wafer W directly tothe interface arm F through an open space in the shelf unit U3 (FIG. 4).

The BCT layer B2 is different from the DEV layer B1 in that the BCTlayer B2 includes three liquid process modules, no shuttle arm E, and noshelf unit U3, while the BCT layer B2 is the same as the DEV layer B1 interms of the other components or units. Three anti-reflection filmcoating modules BCT1 through BCT3 as the liquid process modules areconfigured to dispense a solution of an anti-reflection film onto thewafer W in order to form the anti-reflection film. The shelf unit U1includes plural (e.g., four) hydrophobizing process modules ADH1 throughADH4 where the wafer W undergoes a hydrophobizing process, plural (e.g.,four) heating modules LHP21 through LHP24 where the wafer W is heatedafter the anti-reflection film is coated on the wafer W, and plural(e.g., four) combination ovens or heating modules HHP1 through HHP4.

The shelf unit U2 includes in the area corresponding to the BCT layer B2temperature control modules CPL21, CPL22, a transfer module TRS21, and abuffer module SBU21 where plural wafers W are housed. These modulesCPL21, CPL22, TRS21, SBU21 serve as the first passage portions. Thewafer W is transferred between the anti-reflection film coating modulesBCT1 through BCT3, the shelf unit U1, and the shelf unit U2 by the mainarm A2. In addition, not only the main arm A2 but also the transfer armD (FIG. 2) can access each module in the shelf unit U2. Moreover, thetransfer arm C in the carrier block S1 (FIG. 2) can access the transfermodule TRS21.

The COT layer B3 is configured in substantially the same manner as theBCT layer B2. The COT layer B3 includes three coating modules COT1through COT3 as the liquid process modules that dispense resist solutiononto the wafer W in order to form a resist film. The shelf unit U1includes plural (e.g., nine) heating modules LHP31 through LHP39 wherethe wafer W is heated after the resist film is formed, and a wafer edgeexposure module WEE. The heating modules LHP may include a heating platefor heating the wafer W placed on the heating plate and a cooling plateserving also as a transfer arm that can deliver the wafer W from theheating module to the main arm A3. Namely, the heating modules LHP maybe configured to heat and cool the wafer W.

The shelf unit U2 includes in an area corresponding to the COT layer B3temperature control modules CPL31, CPL32, a transfer module TRS31, abuffer module SBU31, which are stacked one above another and serve asthe first passage portions. The wafer W can be transferred between thecoating modules COT1 through COT3, the shelf unit U1, and the shelf unitU2 by the main arm A3. In addition, not only the main arm A3 but alsothe transfer arm D can access each module in the shelf unit U2.

Next, operations of the resist pattern forming apparatus as configuredabove are explained with reference to FIG. 6, where the anti-reflectionfilm and the resist film are formed as coating films on the wafer W.First, the wafer W housed in the carrier 20 that is transferred into thecarrier block S1 from outside is delivered to the BCT layer B2 throughthe transfer module TRS21 of the shelf unit U2 by the transfer arm C.The wafer W is then transferred through any one of the hydrophobizingprocess modules ADH1 through ADH4, the temperature control module CPL22(21), any one of the anti-reflection film forming modules BCT1 throughBCT3, and any one of the heating modules LHP21 through LHP24 in thisorder by the main arm A2. As a result, the anti-reflection film isformed on the wafer W.

Next, the wafer W is transferred by the main arm A2 to the buffer moduleSBU21 of the shelf unit U2. The wafer W is then transferred from thebuffer module SBU21 to the temperature control module CPL31 (32) of theshelf unit U2 by the transfer arm D. Continuously, the wafer W istransferred through any one of the coating modules COT1 through COT3,any one of the heating modules LHP31 through LHP39, the wafer edgeexposure module WEE in this order by the main arm A3 of the COT layerB3. As a result, the resist film is formed on the anti-reflection film.

Next, the wafer W is transferred from the wafer edge exposure module WEEto the buffer module SBU31 by the main arm A3, and from the buffermodule SBU31 to the temperature control module CPL12 of the shelf unitU2 by the transfer arm D. Then, the wafer W is taken out from thetemperature control module CPL12 by the shuttle arm E. Then, the wafer Wheld by the shuttle arm E is received by the interface arm F of theinterface block S3, and then transferred to the exposure apparatus S4where the wafer W undergoes an exposure process.

After the exposure process, the wafer W is transferred through theinterface arm F, the transfer module TRS41 (42) of the shelf unit U3,and the main arm A1 in this order to the DEV layer B1, where the wafer Wis further transferred through any one of the heating modules PHP1through PHP6, the temperature control module CPL41 (42), any one of thedeveloping modules DEV1 through DEV6, any one of the heating modulesLHA1 through LHA6, and the temperature control module CPL11 in thisorder. As a result, the developing process is finished. Then, the waferW is transferred back by the transfer arm C to the original carrier 20placed on the carrier block S1.

The resist pattern forming apparatus also includes a control portion 7composed of, for example, a computer. The control portion 7 controls theoperations of the main arms A1 through A3, the transfer arm C, thetransfer arm D, the shuttle arm E, the interface arm E, and othercomponents or parts in each module and manages recipes or programs thatcontrol the transfer order of the wafer W and each module. The controlportion 7 is connected to a program storing portion 7 a that storescomputer programs containing groups of steps (instructions) in order tocarry out the operations of each module and the wafer transferoperations so that a predetermined resist pattern is formed in theresist pattern forming apparatus. The computer programs are read outfrom the program storing portion 7 a and executed by the control portion7, so that the resist pattern forming apparatus can operate undercontrol of the control portion 7 in accordance with the computerprogram. The computer program can be loaded to the program storingportion 7 a from a computer readable storing medium 7 b through acorresponding input/output (I/O) device (not shown). An example of thecomputer readable storing medium is a flexible disk, a hard disk, acompact disk, a magneto-optical disk, a memory card, or the like.

FIG. 7 illustrates the configuration of the control portion 7. While thecontrol portion 7 is physically composed of a central processing unit(central processing module), a computer program, a memory device and soon, the following explanation is made supposing that the control portion7 is composed of plural function blocks. In FIG. 7, “70” denotes a busto which a transfer flow producing portion 71, a transfer limiting timecalculating portion 72, a cycle limiting time determining portion 73, acalculation portion 74 for calculating the number of modules to be used,a module selection portion 75 for selecting modules to be used, atransfer schedule producing portion 76, a recipe storing portion 77, anda transfer control portion 78 are connected.

The transfer flow producing portion 71 produces a transfer flow wheretypes of modules listed in accordance with the wafer transfer order areassociated with the corresponding necessary staying times. As statedabove, the necessary staying time is a period of time from when thewafer W is delivered to a module by the main arms A1 through A3 untilwhen the wafer W is ready to be delivered back to the main arms A1through A3 after a predetermined process is finished in the module.

For example, when an operator selects, on a computer display, a processrecipe that is to manage a process to be carried out for the wafer inthe carrier 20 in the carrier block S1 from the process recipes storedin the recipe storing portion 77, the transfer flow is made inaccordance with the selected process recipe. Namely, the process recipeincludes a transfer recipe that determines types of modules to which thewafer W is to be transferred in accordance with a predetermined wafertransfer order, and a processing recipe that determines types ofprocesses carried out in the corresponding modules. With this, when theprocess recipe is selected, the types of modules and the necessarystaying time are automatically selected, so that the transfer flow isproduced. Alternatively, the transfer flow may be produced in such a waythat the operator selects the types of modules and the necessary stayingtime by choosing the types of modules to which the wafer W is to betransferred in the wafer transfer order and then the types of processescarried out in the corresponding modules on a computer screen. In thiscase, the modules selected by the operator are, for example, the coatingmodule COT, the heating module LHP, and the like, rather than theindividual coating module COT1, the individual heating module LHP1, andthe like.

The necessary staying time is defined as a minimum time period from whenthe main arm A (A1 through A3) delivers the wafer W to a certain moduleuntil when the wafer W undergoes the corresponding process in the moduleand is ready to be delivered back to the main arm A, during which thewafer W stays in the module, as stated above. Delivering the wafer W toa certain module by the main arm A means that the wafer W is placed onlift pins provided in a wafer receiving portion of the module from themain arm A. The wafer W being ready to be delivered back to the main armA after the corresponding process is finished means that the wafer W israised by the lift pins in order to deliver the wafer W back to the mainarm A after the process is finished.

The transfer limiting time calculating portion 72 calculates thenecessary transfer time for each of the main arms A1 through A3 inaccordance with the number of the modules that the corresponding arms A1through A3 can access, and then determines the longest necessarytransfer time as the transfer limiting time. Because a transfer speed ofthe main arms A1 through A3 are determined to be constant in advance,the necessary transfer time becomes longer as the number of the modulesthat can be accessed by the corresponding main arms A1 through A3increases, and, conversely, the necessary transfer time becomes shorteras the number of the accessible modules decreases.

The cycle limiting time determining portion 73 determines the necessarytransfer cycle time obtained by dividing the necessary staying time bythe number of the coating modules COT mounted in the resist patternforming apparatus according to this embodiment to be a cycle limitingtime. The cycle limiting time is a period of time necessary to carry outone cycle of the transfer schedule when the wafer W is transferred inaccordance with the transfer schedule.

The calculation portion 74 for calculating the number of modules to beused calculates the necessary transfer cycle time for all the moduleslisted in the transfer flow in accordance with the listing order. Then,the calculation portion 74 determines the number of, for example, theheating modules to be used to be a value obtained by dividing thenecessary staying time in the heating module by the cycle limiting time,or a nearest integer to which this value is raised (instead of thevalue) when the necessary transfer cycle time is less than or equal tothe cycle limiting time. Alternatively, the calculation portion 74determines a new cycle limiting time to be the calculated necessarytransfer cycle time when the necessary transfer cycle time is largerthan the cycle limiting time, and determines the number of, for example,the heating modules to be used to be a value obtained by dividing thenecessary staying time in the heating module by the new cycle limitingtime, or a nearest integer to which this value is raised (instead of thevalue).

The module selection portion 75 selects modules to be used in accordancewith the determined number of the modules to be used. For example, themodules to be used are selected on the computer screen by the operator.

The transfer schedule producing portion 76 produces a transfer schedulein accordance with the transfer flow, the selected modules to be used,and the process recipe to be executed in each module. The transferschedule determines a transfer timing at which each of the wafers Wincluded in a lot is transferred to a predetermined module.Specifically, the transfer schedule is produced by arranging, in timeseries, transfer cycle data that specify a transfer cycle by assigningwafer numbers to the corresponding wafers Wand associating the wafernumber with each module. In this transfer schedule, one cycle of thetransfer schedule is carried out in the new cycle limiting time.

The recipe storing portion 77, which corresponds to a memory portion,stores process recipes in which process conditions applied in processingthe wafer W are recorded, the transfer flow, the transfer schedule andthe like. The transfer control portion 78 refers to the transferschedule and controls the transfer arm C, the main arms A1 through A3,the transfer arm D, the shuttle arm E, the transfer arm C, and theinterface arm F so that the wafer W specified in the transfer cycle datais transferred to the module to which the wafer W has to be transferred,thereby carrying out the transfer cycle.

Next, operational effects of the resist pattern forming apparatusaccording to this embodiment of the present invention are described withreference to FIGS. 8 through 12. First, the operator selects a processrecipe to be executed for the wafers W in the carrier 20 placed on thecarrier block S1 on the computer screen. With this, because module typesare selected in accordance with a transfer order of the wafers W (StepS1) and a process recipe corresponding to a process to be carried out ineach module is selected (Step S2), a transfer flow (table) shown in, forexample, FIG. 9 is produced by the transfer flow producing portion 71(Step S3).

In the transfer flow shown in FIG. 9, the number of the modules mountedin the resist pattern forming apparatus is listed on a module typebasis. In addition, the main arms A (A1 through A3) are listed in such amanner that each of the main arms A is associated with the modules thatthe main arm A concerned can access in the transfer flow. Steps 2through 7 in the transfer flow are carried out in the BCT layer B2;steps 8 through 12 are carried out in the COT layer B3; and steps 15through 20 are carried out in the DEV layer B1. Moreover, “ISHU” of astep 13 generically denotes operations of the shuttle arm E from thetemperature control module CPL12 to the shuttle arm E. Furthermore,“EIF” of a step 14 denotes the interface arm F. Because the modules tobe accessed by each of the main arms A1 through A3 are determined asshown in the transfer flow in FIG. 9, the transfer limiting timecalculating portion 72 can calculate the necessary transfer cycle timesof the main arms A1 through A3 and determine the longest one of thenecessary transfer cycle times to be the transfer limiting time (stepS4). In the illustrated example, the necessary transfer timecorresponding to the main arms A1 and A3 (16 seconds) is determined tobe the transfer limiting time.

Next, the cycle limiting time determining portion 73 calculates thenecessary transfer cycle time with respect to the coating module COT,compares the calculated necessary transfer cycle time with the transferlimiting time determined above, and determines the longer one of thecalculated necessary transfer cycle time and the transfer limiting timeto be the cycle limiting time (step S5). For example, because thenecessary staying time for the coating modules COT is 60 seconds and thethree coating modules COT are mounted in the resist pattern formingapparatus, the necessary transfer cycle time is 20 seconds (thenecessary staying time (60 seconds) divided by the number of the coatingmodules (3)), which means the necessary transfer cycle time is longerthan the transfer limiting time (16 seconds). Therefore, the necessarytransfer cycle time is now determined to be the cycle limiting time.However, the number of the modules of the same type can be determined inorder that the transfer limiting time of the main arms A is notdetermined to be the cycle limiting time in order to improve the processthroughput. In this case, calculating the transfer limiting time of themain arms A and comparing the calculated necessary transfer cycle timewith the transfer limiting time can be omitted, thereby directlydetermining the necessary transfer cycle time of the coating modules COTto be the cycle limiting time.

Next, the calculation portion 74 for calculating the number of modulesto be used obtains the number of the modules of the same type to be usedin accordance with the listing order in the transfer flow (step S6). Anexample of Step S6 is described with reference to flowcharts in FIGS. 10and 11. First, an instruction is output to start the calculation from afirst module listed in the transfer flow at Step S11, and then it isdetermined whether there is the necessary staying time for the firstmodule at Step S12. When there is not the necessary staying time (StepS12: N), this procedure proceeds to Step S20, where a next instructionis output to calculate the number of the next module in the transferflow. Because the necessary staying time is not written with respect tothe first module, which is the transfer module TRS, in the transfer flowshown in FIG. 9, it is then determined whether there is the necessarystaying time for the next module, which is the hydrophobizing processmodule ADH.

On the other hand, when it is determined at Step S12 that there is thenecessary staying time for the module concerned (Step S12: Y), it isdetermined whether the necessary transfer cycle time for the same moduleis within the cycle limiting time at Step S13. When the necessarytransfer cycle time is within the cycle limiting time (Step S13: Y),this procedure proceeds to Step S14. Alternatively, when the necessarytransfer cycle time exceeds the cycle limiting time (Step S13: N), thenecessary transfer cycle time for this module is determined to be a newcycle limiting time Step S15, and this procedure returns to Step S13. Inthe case of the hydrophobizing process modules ADH in the transfer flowin FIG. 9, because the necessary transfer cycle time is 15 seconds (thenecessary staying time (60 seconds) divided by the number of thehydrophobizing process modules ADH (4)), the procedure proceeds to StepS14.

At Step S14, m is set to be 1, and then the procedure proceeds to StepS16, where it is determined whether a value obtained by dividing thenecessary staying time for the module concerned (e.g., ADH) by (thenumber of the modules−m) is within the cycle limiting time. When thevalue is within the cycle limiting time (Step S16: Y), the procedureproceeds to Step S17, where the m is incremented by 1, and then theprocedure returns to Step S16. Alternatively, when the value exceeds thecycle limiting time (Step S16: N), the procedure proceeds to Step S18,where the number of the modules to be used is determined by the nextexpression (1):the number of the modules to be used=the number of the modules mountedin the resist pattern forming apparatus−m+1  (1)

In the case of the hydrophobizing process modules ADH in FIG. 9, it isdetermined at Step S16 that the value within the cycle limiting timebecause (the necessary staying time (60 seconds)/(the number of themounted modules (4)−m (m=1))) is 20 seconds, and m becomes 2 at StepS17. Then, it is determined again at Step S16 whether the value iswithin the cycle limiting time. In this case, because the value (thenecessary staying time (60 seconds)/(the number of the modules (4)−m(m=2))) is 30 seconds, which exceeds the cycle limiting time, and thusthe number of the modules to be used is determined at Step S18 inaccordance with the expression (1). Namely, the number of thehydrophobizing process modules ADH is determined to be 3 (4−2+1).

After the number of the modules to be used is determined at Step S18,the procedure proceeds to Step S19, where it is determined whether themodule whose number is obtained is the last module in the transfer flow.When the module is the last one listed in the transfer flow (Step S19:Y), other procedures shown in FIG. 11 are carried out (described later).Alternatively, when the module is not the last one (Step S19: N), theprocedure returns to Step S12 via Step S20 and Step S12 and beyond arecarried out. With this, the number of the modules to be used is obtainedfor the next module listed in the transfer flow.

As stated, the number of the modules to be used is obtained for all themodules listed in the transfer flow, namely from the transfer module TRSthrough the temperature control module CPL (step 20) in accordance withthe flowchart in FIG. 10. Here, the procedure in accordance with thesame flowchart is explained again taking as an example the heatingmodule LHP listed at step 6 in the transfer flow in FIG. 9. As listed inthe transfer flow, because the necessary staying time is 90seconds andthere are four heating modules LHP mounted in the resist pattern formingapparatus, the necessary transfer cycle time is 22.5 seconds, whichexceeds the cycle limiting time of 20 seconds at this time. Then, thecycle limiting time is newly set to be 22.5 seconds at Step S15, and theprocedure proceeds to Step S13. Then, Step S13 and beyond are carriedout under the new cycle limiting time of 22.5 seconds.

At Step S16 in the flowchart of FIG. 10, it is determined that thenecessary transfer cycle time exceeds the new cycle limiting time (22.5seconds) because the value obtained by dividing the necessary stayingtime (90 seconds) by (the number of the mounted heating modules LHP(4)−1 (m=1)) is 30 seconds. Then, the procedure proceeds to Step S18,where the number of the heating modules LHP to be used is calculated to4 (4−1+1) following the expression (1).

Next, the heating module LHP listed at step 10 of the transfer flow inFIG. 9 is taken as an example. Because the necessary staying time is 90seconds and the number of the mounted heating modules LHP is 9, thenecessary transfer cycle time is 10 seconds, which is within the newcycle limiting time of 22.5 seconds (Step S13: Y). Therefore, theprocedure proceeds to Step S16, where it is determined whether the valueobtained by dividing the necessary staying time (90 seconds) by (thenumber of the mounted heating modules LHP (9)−m (1)) is within the newcycle limiting time. Because the value (11.5 seconds) is within the newcycle limiting time (22.5 seconds), the procedure returns to Step S16after m is incremented to 2 at Step S17. After Steps S16 and S17 arerepeated until m becomes 6, the value obtained by dividing the necessarystaying time (90 seconds) by (the number of the mounted heating modulesLHP (9)−m (6)) is 30 seconds, which exceeds the new cycle limiting timeof 22.5 seconds (Step S16: N). Therefore, the procedure proceeds to StepS18, where the number of the heating modules LHP to be used isdetermined to be 4 (9−6+1) in accordance with the expression (1).

In such a manner, the calculation portion 74 for calculating the numberof modules to be used calculates the necessary transfer cycle time forall the modules listed in the transfer flow in accordance with thelisting order, and determines the number of the modules to be used to bea value obtained by dividing the necessary staying time in the modulesby the cycle limiting time, or a nearest integer to which this value israised (instead of the value) when the necessary transfer cycle time isless than or equal to the cycle limiting time. Alternatively, thecalculation portion 74 determines a new cycle limiting time to be thecalculated necessary transfer cycle time when the necessary transfercycle time is larger than the cycle limiting time, and determines thenumber of the modules to be used to be a value obtained by dividing thenecessary staying time in the modules by the new cycle limiting time, ora nearest integer to which this value is raised (instead of the value).The numbers of the modules to be used, which are obtained in thismanner, are listed in the transfer flow as shown in FIG. 12.

Continuing from Step S6 (FIG. 8), the number of the modules to be usedis recalculated for all the modules listed in the transfer flow inaccordance with the listing order at Step S7. This recalculation iscarried out in accordance with the flowchart shown in FIG. 11. Thisflowchart is different from the previous flowchart shown in FIG. 10 inthat the flowchart in FIG. 11 lacks Step S15 that exists in the previousflowchart. This is because the necessary transfer cycle time has alreadybeen calculated for all the modules and thus the longest one of thenecessary transfer cycle times has been determined to be the cyclelimiting time. Namely, there is no need to set a new cycle limitingtime. However, the remaining parts of the flowchart in FIG. 11 are thesame as the previous one in FIG. 10, and therefore repetitiveexplanations about the remaining parts are omitted.

Next, at Step S8 (FIG. 8), the operator selects modules to be used byusing a module-specific identification number through the moduleselection portion 75 for selecting modules to be used. For example, theoperator can specify LHP1, LHP2, LHP3, and LHP4 when he or she selectsfour heating modules (LHP) in the COT layer B3. Then, the transferschedule producing portion 76 produces a transfer schedule where thetransfer order and the wafer number of the wafer W are associated witheach other. In the coater/developer, the wafer W is transferred inaccordance with the transfer order and a predetermined resist patternforming process is carried out for the wafer W. In this transferschedule, one cycle of the transfer schedule is carried out in the newcycle limiting time of 22.5 seconds.

In such a configuration, when the operator selects the modules to beused in accordance with the transfer order and selects the processrecipe corresponding to the process carried out in each of the modules,the number of the modules to be used is automatically calculated foreach of the modules. Therefore, the exact number of the modules to beused is obtained without relying on the operator's experience or guess.In this case, because the number of the modules to be used is determinedin accordance with the cycle limiting time of the modules, the numbermeans the necessary minimum number that enables one cycle of thetransfer schedule to be carried out within the cycle limiting time.

Therefore, according to the coater/developer of this embodiment, sincethe transfer schedule does not include modules that are not used, incontrast to the related art coater/developer, unnecessary temperaturecontrol for, for example, the heating modules LHP, the hydrophobizingprocess modules ADH, and the like that are not used can be avoided,thereby saving electricity and reducing running cost.

In addition, because the number of the modules to be used isrecalculated after the number of the modules to be used has beencalculated for all the modules listed in the transfer flow, even whenthe necessary transfer cycle time for, for example, the last module inthe transfer flow is set to be a new cycle limiting time, the number ofthe modules to be used can be recalculated under the new cycle limitingtime, thereby accurately determining the number of the modules to beused.

While the number of the modules to be used can be determined as statedabove, the number of the modules to be used may be determined in adifferent manner in accordance with a flowchart shown in FIG. 13. Inthis example, Steps S31 through S34 in FIG. 13 are the same as Step S1through S4 in FIG. 8, respectively. However, the cycle limiting timedetermining portion 73 calculates the necessary transfer cycle time forall the modules listed in the transfer flow, compares the longest one ofthe necessary transfer cycle times with the transfer limiting time, anddetermines the cycle limiting time to be the longer one of the longestnecessary transfer cycle time and the transfer limiting time at StepS35. Even in this case, Step S34 for determining the transfer limitingtime and a step for comparing the longest necessary transfer cycle timewith the transfer limiting time may be omitted, so that the longestnecessary transfer cycle time may be determined to be the cycle limitingtime.

The calculation portion 74 for calculating the number of modules to beused determines the number of, for example, the heating modules to beused to be a value obtained by dividing the necessary staying time forthe heating modules by the cycle limiting time, or a nearest integer towhich this value is raised (Step S6). This step is specificallyexplained with reference to a flowchart in FIG. 14. First, aninstruction is output to start calculation from a first module in thetransfer flow at Step S41, and then it is determined whether there isthe necessary staying time for the first module at Step S42. When thereis not the necessary staying time (Step S42: N), this procedure proceedsto Step S48, where a next instruction is output to proceed to the nextmodule in the transfer flow.

On the other hand, when there is the necessary staying time for thefirst module (Step S42: Y), the procedure proceeds to Step S44 via StepS43, where it is determined whether a value obtained by dividing thenecessary staying time by (the number of the mounted modules−1) iswithin the cycle limiting time. When the value is within the cyclelimiting time (Step S44: Y), the procedure proceeds to Step S45, where mis incremented by 1, and returns to the Step S44. On the other hand,when the value exceeds the cycle limiting time (Step S44: N), theprocedure proceeds to Step S46, where the number of the modules to beused is calculated in accordance with the expression (1).

After the number of the modules to be used is determined at Step S46,the procedure proceeds to Step S47, where the module is the last listedin the transfer flow. When the module is not the last one in thetransfer flow (Step S47: N), the procedure proceeds to Step S48, andthen the calculation is carried out for the next module. Alternatively,when the module is the last one in the transfer flow (Step S47: Y), theprocedure is completed.

In this example, before the number of the modules to be used iscalculated, the longest necessary transfer time of the necessarytransfer times obtained for all the modules listed in the transfer flowis determined to be the cycle limiting time. Therefore, the cyclelimiting time is not newly set when the number of the modules to be usedis calculated, which facilitates the calculation. In addition, becausethe cycle limiting time is not newly set when the number of the modulesto be used is calculated, the recalculation explained with reference toFIG. 11 is not required.

The above calculation of the number of the modules to be used may becarried out only for the heating modules LHP, PHP, LHA, and the like.Even if such calculation is not carried out for the temperature controlmodules and, as a result, there are the temperature control moduleswhere the temperature is maintained at a predetermined temperature whilenot being used, those temperature control modules consume only a smallamount of electricity.

In addition, it is not necessary to recalculate the number of themodules to be used (FIG. 11). This is because the number of the modulesto be used can be accurately obtained for some of the heating modules bythe calculation of the number of the modules to be used (FIG. 10), whichcan save electricity.

Moreover, while the heating modules are selected by the operator in theabove embodiment, the heating modules can be selected, for example,based on a process temperature of a heating module that is used for aprevious lot, a temperature of a heating module that is not used for theprevious lot, and a process temperature at which a lot is to beprocessed in the immediate run in other embodiments of the presentinvention. With this, the heating modules can be selected so that atemperature setting time is reduced.

Specifically, when the process temperature of the heating module usedfor the previous lot is the same as the process temperature at which theimmediate lot is to be processed, the heating module used for theprevious lot is selected in the immediate run. In this case, setting adifferent temperature is not necessary. Alternatively, when the processtemperature of the heating module used for the previous lot is not thesame as the temperature at which the immediate lot is to be processedand there are heating modules not used for the previous lot, the unusedheating modules can be selected in the immediate run. In the following,it is assumed that the previous lot has 20 wafers referred to as wafersW1 through W20. When the same heating module is used for the immediatelot, temperature control for the immediate lot starts right after thewafer W20 is processed. Therefore, the module has to be in an idle stateuntil the temperature is stabilized at the process temperature for theimmediate lot. On the other hand, when a different heating module notused for the previous lot is used for the immediate lot, the temperaturecontrol can start before the last wafer W20 is finished. Therefore,there is no waiting time between the previous and the immediate lotswhen the heating module not used for the previous lot is selected in theimmediate run.

The above manner of selecting the heating modules is more specificallyexplained taking an example of six heating modules LHP1 through LHP6mounted in the coater/developer. It is assumed in the following that theheating modules LHP1, LHP2, LHP3, and LHP4 are used for the previouslot, four out of the six heating modules LHP1 through LHP6 are used forthe immediate lot, and the process temperatures are different betweenthe previous and the immediate lots.

In this case, the heating modules LHP5 and LHP6, which are not used forthe previous lot, are selected for the immediate lot and can betemperature-controlled while the previous lot is being processed so thatthese heating modules LHP5 and LHP6 are ready for the immediate runbefore the previous run is finished. Therefore, a first wafer B1 of theimmediate lot can be transferred into the heating module LHP5 and asecond wafer B2 of the immediate lot can be transferred into the heatingmodule LHP6 right after the previous run is finished.

On the other hand, because wafers in the previous lot are transferredinto the heating modules LHP1, LHP2, LHP3, and LHP4 in this order, whena second to last wafer is in the heating module LHP3, the heatingmodules LHP1 and LHP2 can be empty, which means the temperature controlto a process temperature for the immediate lot can start before theprevious run is finished. In addition, because the first wafer B1 of theimmediate lot is transferred into the heating module LHP5 and the secondwafer B2 of the immediate lot is transferred into the heating moduleLHP6, there is enough time from when the heating modules LHP1 and LHP2become empty to when wafers B3 and B4 of the immediate lot areintroduced into the heating modules LHP1 and LHP2, respectively.Therefore, when the heating modules LHP1 and LHP2 are selected for theimmediate lot, the temperature setting time is substantively reduced.However, in order to carry out this way of selecting the heatingmodules, the operator has to specify the transfer order of the wafers,calculate the number of the heating modules to be used, and select theheating modules to be used.

While the coater/developer according to the embodiment of the presentinvention is used to process a semiconductor wafer, the coater/developeraccording to other embodiments of the present invention may be used toprocess a glass substrate for a Liquid Crystal Panel (LCD substrate). Inaddition, the coater/developer according to the embodiment of thepresent invention may have a different configuration. For example, thecoating modules and the developing modules may be arranged in the sameblock. Additionally, the type, the number, and the arrangement ofmodules mounted in the coater/developer may be optionally determined,and the transfer order may also be optionally determined.

1. A coater/developer apparatus having a carrier block where a carrierhousing plural substrates is placed and that has a transfer unit fortransferring one of the substrates into and out from the carrier, and aprocess block where a coating film is formed on the substratetransferred from the carrier by the transfer unit and a developingprocess is carried out with respect to the substrate after an exposureprocess, wherein the process block includes plural liquid processmodules where a coating solution is coated on the substrate, pluralheating modules where the substrate is heated, plural temperaturecontrol modules where a temperature of the substrate is controlled, anda substrate transferring unit configured to transfer a first substrateout from a first module of the plural liquid process modules, the pluralheating modules, and the plural temperature control modules, the firstsubstrate having been processed in the first module, and transfer asecond substrate into the first module, the second substrate having beenprocessed in a second module located upstream from the first module byone process step in a wafer transfer route, and a controller furthercomprising: a transfer flow producing portion that produces, inaccordance with a process recipe concerning the carrier in the carrierblock, a transfer flow where a type of the modules listed in accordancewith a substrate transfer order in the transfer flow is associated witha necessary staying time from when the substrate is transferred into anyone of the modules by the substrate transferring unit to when thesubstrate undergoes a corresponding process in the module and is readyto be transferred back to the substrate transferring unit, the necessarystaying time being determined corresponding to the type of the modules;a cycle limiting time determining portion that calculates a necessarytransfer cycle time by dividing the necessary staying time by the numberof the corresponding modules mounted in the coater/developer apparatus,the necessary transfer cycle time being obtained with respect to themodules listed in the transfer flow, and determines the longestnecessary transfer cycle time to be a cycle limiting time; and adetermining portion that calculates a value by dividing the necessarystaying time by the cycle limiting time and determines the number of themodules to be used to be one of the value and a nearest integer to whichthe value is raised, the number of the modules to be used beingdetermined with respect to the heating modules listed in the transferflow.
 2. A coater/developer apparatus having a carrier block where acarrier housing plural substrates is placed and that has a transfer unitfor transferring one of the substrates into and out from the carrier,and a process block where a coating film is formed on the substratetransferred from the carrier by the transfer unit and a developingprocess is carried out with respect to the substrate after an exposureprocess, wherein the process block includes plural liquid processmodules where a coating solution is coated on the substrate, pluralheating modules where the substrate is heated, plural temperaturecontrol modules where a temperature of the substrate is controlled, anda substrate transferring unit configured to transfer a first substrateout from a first module of the plural liquid process modules, the pluralheating modules, and the plural temperature control modules, the firstsubstrate having been processed in the first module, and transfer asecond substrate into the first module, the second substrate having beenprocessed in a second module located upstream from the first module byone process step in a wafer transfer route, and a controller furthercomprising: a transfer flow producing portion that produces, inaccordance with a process recipe concerning the carrier in the carrierblock, a transfer flow where a type of the modules listed in accordancewith a substrate transfer order in the transfer flow is associated witha necessary staying time from when the substrate is transferred into anyone of the modules by the substrate transferring unit to when thesubstrate undergoes a corresponding process in the module and is readyto be transferred back to the substrate transferring unit, the necessarystaying time being determined corresponding to the type of the modules;a cycle limiting time determining portion that determines the cyclelimiting time to be a necessary transfer cycle time obtained by dividingthe necessary staying time in a coating module that coats a resistsolution on the substrate and is included in the plural liquid processmodules by the number of the coating modules mounted in thecoater/developer apparatus; and a determining portion that calculatesthe necessary transfer cycle time with respect to the modules listed inthe transfer flow in accordance with the listing order, determines thenumber of the heating modules to be used to be one of a value obtainedby dividing the necessary staying time in the heating modules by thecycle limiting time and a nearest integer to which the value is raisedwhen the necessary transfer cycle time is less than or equal to thecycle limiting time, and determines the necessary transfer cycle time tobe a new cycle limiting time when the necessary transfer cycle time isgreater than the cycle limiting time and then determines the number ofthe heating modules to be used to be one of a value obtained by dividingthe necessary staying time in the heating modules by the new cyclelimiting time and a nearest integer to which the value is raised.
 3. Thecoater/developer apparatus of claim 2, wherein the determining portionrecalculates the number of the modules to be used with respect to themodules listed in the transfer flow in the listing order after thedetermining portion calculates the number of the modules to be used withrespect to the modules listed in the transfer flow in the listing order.